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Record Information
Creation Date2012-09-11 18:41:51 UTC
Update Date2016-02-11 02:21:28 UTC
Secondary Accession NumbersNone
Metabolite Identification
Common Name(±)-erythro-Isoleucine
Description(±)-erythro-Isoleucine is a flavouring ingredient, dietary supplement, nutrient Branched chain amino acids (BCAA) are essential amino acids whose carbon structure is marked by a branch point. These three amino acids are critical to human life and are particularly involved in stress, energy and muscle metabolism. BCAA supplementation as therapy, both oral and intravenous, in human health and disease holds great promise. "BCAA" denotes valine, isoleucine and leucine which are branched chain essential amino acids. Despite their structural similarities, the branched amino acids have different metabolic routes, with valine going solely to carbohydrates, leucine solely to fats and isoleucine to both. The different metabolism accounts for different requirements for these essential amino acids in humans: 12 mg/kg, 14 mg/kg and 16 mg/kg of valine, leucine and isoleucine respectively. Furthermore, these amino acids have different deficiency symptoms. Valine deficiency is marked by neurological defects in the brain, while isoleucine deficiency is marked by muscle tremors. BCAA are decreased in patients with liver disease, such as hepatitis, hepatic coma, cirrhosis, extrahepatic biliary atresia or portacaval shunt; aromatic amino acids (AAA)-tyrosine, tryptophan and phenylalanine, as well as methionine-are increased in these conditions. Valine, in particular, has been established as a useful supplemental therapy to the ailing liver. All the BCAA probably compete with AAA for absorption into the brain. Supplemental BCAA with vitamin B6 and zinc help normalize the BCAA:AAA ratio. The BCAA are not without side effects. Leucine alone, for example, exacerbates pellagra and can cause psychosis in pellagra patients by increasing excretion of niacin in the urine. Leucine may lower brain serotonin and dopamine. (±)-erythro-Isoleucine is a dose of 3 g of isoleucine added to the niacin regime has cleared leucine-aggravated psychosis in schizophrenic patients. Isoleucine may have potential as an antipsychotic treatment. Leucine is more highly concentrated in foods than other amino acids. (±)-erythro-Isoleucine is a cup of milk contains 800 mg of leucine and only 500 mg of isoleucine and valine. (±)-erythro-Isoleucine is a cup of wheat germ has about 1.6 g of leucine and 1 g of isoleucine and valine. The ratio evens out in eggs and cheese. (±)-erythro-Isoleucine is one egg and an ounce of most cheeses each contain about 400 mg of leucine and 400 mg of valine and isoleucine. The ratio of leucine to other BCAA is greatest in pork, where leucine is 7 to 8 g and the other BCAA together are only 3 to 4 g. (
Chemical FormulaC6H13NO2
Average Molecular Weight131.1729
Monoisotopic Molecular Weight131.094628665
IUPAC Name2-amino-3-methylpentanoic acid
Traditional NameL(+)-isoleucine
CAS Registry Number443-79-8
InChI Identifier
Chemical Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as alpha amino acids. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon).
KingdomOrganic compounds
Super ClassOrganic acids and derivatives
ClassCarboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
Direct ParentAlpha amino acids
Alternative Parents
  • Alpha-amino acid
  • Methyl-branched fatty acid
  • Branched fatty acid
  • Amino fatty acid
  • Fatty acyl
  • Fatty acid
  • Monocarboxylic acid or derivatives
  • Carboxylic acid
  • Hydrocarbon derivative
  • Primary amine
  • Organooxygen compound
  • Organonitrogen compound
  • Primary aliphatic amine
  • Carbonyl group
  • Amine
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External DescriptorsNot Available
StatusExpected but not Quantified
  • Food
  • Nutrient
  • Flavoring Agent
Cellular locations
  • Cytoplasm
  • Extracellular
Physical Properties
StateNot Available
Experimental Properties
Melting Point275 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility21.4 mg/mL at 25 °CNot Available
LogP-1.70Not Available
Predicted Properties
Water Solubility114.0 mg/mLALOGPS
pKa (Strongest Acidic)2.79ChemAxon
pKa (Strongest Basic)9.59ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area63.32 Å2ChemAxon
Rotatable Bond Count3ChemAxon
Refractivity34.09 m3·mol-1ChemAxon
Polarizability14.19 Å3ChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectrum TypeDescriptionSplash Key
GC-MSGC-MS Spectrum - GC-MS (1 TMS)splash10-000i-9200000000-5690865bab18b5b529cdView in MoNA
GC-MSGC-MS Spectrum - GC-MS (2 TMS)splash10-0a4i-0910000000-5bb0521c0ebf8a910a75View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0019-9600000000-c89a1d3a5cd18f7067c6View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-000i-9000000000-0ec2d659f4b36953fc35View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0a4i-9000000000-a1549b562a6cbd32eff5View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-001i-2900000000-4adf1ee6b81d40f1574aView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-001i-5900000000-5b598d31f2916eb03739View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0ab9-9000000000-eb5a6b5a60bf1dce153dView in MoNA
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid LocationsNot Available
Tissue LocationNot Available
PathwaysNot Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB012123
KNApSAcK IDNot Available
Chemspider ID769
KEGG Compound IDC16434
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkNot Available
NuGOwiki LinkHMDB33923
Metagene LinkHMDB33923
METLIN IDNot Available
PubChem Compound791
PDB IDNot Available
ChEBI ID38264
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Yannai, Shmuel. (2004) Dictionary of food compounds with CD-ROM: Additives, flavors, and ingredients. Boca Raton: Chapman & Hall/CRC.